title: Relative bioavailability of terbutaline to the lung following inhalation, using urinary excretion.
abstract: OBJECTIVE
  The aim of the study was to determine the relative lung and systemic bioavailability of terbutaline.
  
  
  METHODS
  On separate days healthy volunteers received 500 µg terbutaline study doses either inhaled from a metered dose inhaler or swallowed as a solution with and without oral charcoal. Urine samples were provided at timed intervals post dosing.
  
  
  RESULTS
  Mean (SD) urinary terbutaline 0.5 h post inhalation, in 12 volunteers, with (IC) and without (I) oral charcoal and oral (O) dosing was 7.4 (2.2), 6.5 (2.1) and 0.2 (0.2) µg. I and IC were similar and both significantly greater than O (P<0.001). Urinary 24 h terbutaline post I was similar to IC + O. The method was linear and reproducible, similar to that of the urinary salbutamol method.
  
  
  CONCLUSIONS
  The urinary salbutamol pharmacokinetic method post inhalation applies to terbutaline. Terbutaline study doses can replace routine salbutamol during these studies when patients are studied.
authors.affiliation: Faculty of Pharmacy, University of Beni Suef, Beni Suef, Egypt.
authors.forename: Mohamed E
authors.initials: ME
authors.lastname: Abdelrahim
authors.forename: Khaled H
authors.initials: KH
authors.lastname: Assi
authors.forename: Henry
authors.initials: H
authors.lastname: Chrystyn
mesh_terms: D000280:Administration, Inhalation; D058666:Adrenergic beta-2 Receptor Agonists / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000652:urine; D000328:Adult; D001682:Biological Availability; D002606:Charcoal / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008168:Lung / Q000378:metabolism; D008297:Male; D036501:Metered Dose Inhalers / Q000706:statistics & numerical data; D013726:Terbutaline / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000652:urine; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D058666:Adrenergic beta-2 Receptor Agonists; D002606:Charcoal; D013726:Terbutaline